Aerostat with phase change adjustment airbag

Abstract

An aerostat with a phase change adjustment airbag, the aerostat comprising a main airbag (302); a load nacelle (308), which is used for containing a mission apparatus and a mission load; a phase chang

Description

AEROSTAT WITH PHASE CHANGE ADJUSTMENT AIRBAG CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No.2020115946986, filed on December 29, 2020, the contents of which are hereby incorporated by reference. TECHNICAL FIELD

[0002] The application relates to a kind of high-altitude balloon, and in particular to a high-altitude balloon with phase change adjustment airbag. BACKGROUND

[0003] A high-altitude balloon is composed of a sphere system, and a equipment load basket, etc. The sphere is filled with a lift gas with a certain mass lighter than air to generate a buoyancy, so that the balloon rises and then keeps at an appropriate height. The equipment load basket contains energy, control, avionics, communication, recovery and other equipment and task loads. Broadly speaking, high-altitude balloons are divided into conventional zero-pressure natural balloons, large super pressure balloons, small super pressure balloons, infrared hot air balloons, etc.

[0004] The zero-pressure balloon generally adopts an open structure with an exhaust pipe at the bottom. When launching, with the balloon rising and an atmospheric pressure decreasing, the lift gas in the sphere expands rapidly. When a rising limit is reached, the lift gas fills the whole sphere, the excess lift gas is discharged from the exhaust pipe at the bottom, and the gravity and buoyancy of the balloon reach a balance. Due to comprehensive factors such as direct solar radiation, ground albedo radiation and infrared radiation of geogas, a temperature of the gas inside the sphere is obviously higher than that of an external atmosphere, and an expansion of the lift gas inside the sphere leads to an increase of the internal and external pressure difference. In order to prevent the balloon from expanding and causing the sphere to burst, the exhaust pipe at the bottom of the balloon exhausts a part of the lift gas. At night, the solar radiation disappears, the temperature and the pressure of the internal lift gas drop, and the buoyancy of the balloon decreases, which causes the height to drop. When the height is too low, a certain ballast causes the height to drop. When the height is too low, a certain ballast (such as water or sand) may be thrown. However, the ballast and the lift gas carried by the balloon are non- renewable resources in the air, so a frequency and an amplitude of a height adjustment are very limited. Once there is no excess ballast to throw, and the residual lift gas is not enough to provide the minimum buoyancy required by an effective working height, a task has to be finished, and an effective working duration is extremely short.

[0005] An super pressure single body relies on a special structural design and high-strength film materials to passively resist the increase of the pressure difference. However, the pressure difference resisted by this passive way is limited. Due to drastic changes of irradiation conditions in middle and low latitudes of the earth, the super pressure single body is relatively large. Therefore, the large super pressure single body with a volume of tens of thousands of cubic meters or more only carries out its flight mission in extremely daytime areas at high latitudes of the earth. In addition, the super pressure single body does not have an ability to adjust the working height.

[0006] While the working height of a composite body 1s adjusted by an internal airbag, the increase of the pressure difference may be exacerbated to a greater extent: when the air is discharged to raise the height, the internal and external pressures decrease simultaneously; when the air is absorbed to reduce the height, the internal and external pressures increase simultaneously. Therefore, it is difficult to control the pressure difference and the height simultaneously only by the airbag, and there is a typical under-actuated problem. Actually, the internal airbag is not suitable as a means to keep the pressure difference in theory, and an influence of a temperature difference between day and night leads to different chain reactions. (1) During the day, due to the comprehensive factors such as the direct solar radiation, the ground albedo radiation, and the infrared radiation of geogas, the temperature of the air inside the sphere is obviously higher than that of the external atmosphere; if the air is not exhausted, the internal and external pressure differences may exceed a stress range of an envelope, thus reducing a service life of the envelope. However, the exhausted gas reduces the gravity of the system, increases a net buoyancy, and affect a height maintenance. (2) At night, as the temperature of the gas inside the sphere decreases and the pressure decreases, air needs to be filled to maintain the pressure, thus increasing the gravity of the system, decreasing the net buoyancy, and affecting the height maintenance.

[0007] Although a rotating Yin-yang body is mentioned in the Chinese invention entitled "Balloon Height Control by Density Adjustment And / or Volume Adjustment" with an application number of 201380036079.7, in essence, the rotating Yin-yang body only actively controls a pressure difference theoretically. First, as stated in paragraph 0034 of this disclosure, it is impossible to keep the pressure difference by the rotating Yin-yang body at night, so the rotating Yin-yang body is not a way for a day-night cycle. Secondly, claims 16 and 17 and paragraphs 0129-0132 of the disclosure state that one or more offset fans, thrust plates or thrust deflectors are controlled and operated by a motor or a servo motor to make a directional sleeve release compressed air, and an airbag is rotated through a universal support or a spherical roller bearing, etc. Actually, there are two fatal problems here: first, the higher the working height of the high-altitude balloon, the larger its volume (a surface area of a giant high-altitude balloon in an order of millions of cubic meters may cover many football fields), and the greater the moment of inertia; because a very large power consumption is required to rotate the whole balloon through an active control, so the active control is actually difficult to achieve; second, rotating a sphere aggravates a twist of a lower basket. It should be noted that an attitude of the basket ultimately determines a working quality of the task equipment and a user satisfaction. Even if the huge sphere above is not rotated, it is necessary to attach great importance to a reverse twist control of the twist caused by a wind field disturbance and to a decoupling from an azimuth control.

[0008] As a passive heating scheme, the infrared hot air balloon alleviates adverse changes of the pressure difference to a certain extent. However, the infrared hot air balloon also has adverse effects on the maintenance of the working height. The altitude at night is 10 km lower than that during the day, and the task is finished only after the fifth day.

[0009] To sum up, there is still a current lack of an active control scheme that effectively maintains the pressure difference of the balloon and realizes the day-night cycle; therefore, a flight safety of the balloon is not fundamentally guaranteed, thus affecting a lasting dwell capacity of the high-altitude balloon; moreover, there is no complete driving means to realize a coordination between a pressure difference maintenance and a height control, so an effective working quality of the high-altitude balloon is weaken. SUMMARY

[0010] In order to solve the shortcomings of the above technology, the application provides a high-altitude balloon with phase change adjustment airbag,

[0011] In order to solve the above technical problems, a technical scheme adopted by the application is as follows: a high-altitude balloon with phase change adjustment airbag includes a main airbag; a load basket for equipping task equipment and loads; a phase change adjustment airbag for directly or indirectly adjusting a pressure difference of the high-altitude balloon to maintain the pressure difference within a safety range when a height of the balloon changes; a phase change working medium gas for filling the phase change adjustment airbag; and phase change equipment for regulating and controlling a volume of the phase change working medium gas in the phase change adjustment airbag; the phase change equipment includes a liquefaction / condensation device for liquefying / condensing the phase change working medium gas; a gasification / sublimation device for gasifying / sublimating the phase change working medium; a storage tank for storing a liquid / solid working medium; phase change electronics and accessories; and a control system for controlling the phase change equipment and changing the volume of the phase change adjustment airbag without changing a weight of a whole balloon system, so as to cause an appropriate change of the balloon pressure difference and keep the balloon pressure difference within the safety range.

[0012] In an embodiment, the phase change adjustment airbag is one of a single configuration inside the main airbag, a single configuration outside the main airbag, a composite configuration inside the main airbag, a composite configuration outside the main airbag, a single internal-external hybrid configuration and a composite internal-external hybrid configuration.

[0013] In an embodiment, the phase change adjustment airbag arranged outside the main airbag changes the volume of the phase change adjustment airbag through the phase change equipment, thereby directly changing the height of the balloon and indirectly changing the pressure difference of the balloon, so that the pressure difference of the balloon is kept within the safety range.

[0014] In an embodiment, when the pressure difference of the main airbag exceeds a conservative upper limit, the phase change working medium gas in the phase change adjustment airbag is liquefied / condensed by the liquefaction / condensation device, so that the volume of the phase change adjustment airbag is reduced, which directly causes a buoyancy and the height of the balloon to decrease, and then an ambient atmospheric pressure increases, thus indirectly causing the pressure difference of the main airbag to decrease;

[0015] when the pressure difference of the main airbag exceeds a conservative lower limit, the liquid / solid working medium in the storage tank is gasified / sublimated into the phase change working medium gas by the gasification / sublimation device, and then the gas is transported to the phase change adjustment airbag, so that the volume of the phase change adjustment airbag increases, directly causing the buoyancy and the height of the balloon to increase, and then the ambient atmospheric pressure decreases, thus indirectly causing the pressure difference of the balloon to increase.

[0016] In an embodiment, the phase change adjustment airbag arranged in the main airbag directly causes the appropriate change of the balloon pressure difference by changing the volume of the internal phase change adjustment airbag, so that the balloon pressure difference is kept within the safety range.

[0017] In an embodiment, when the pressure difference of the main airbag exceeds the conservative upper limit, the phase change working medium gas in the phase change adjustment airbag is liquefied / condensed by the liquefaction / condensation device, so that the volume of the phase change adjustment airbag is reduced and an expansion space is left for the lift gas, and then the volume of the lift gas expands, an internal pressure and the pressure difference of the main airbag decrease, and a rising trend of the pressure difference is slowed down;

[0018] when the pressure difference of the main airbag exceeds the conservative lower limit, the liquid / solid working medium in the storage tank is gasified / sublimated by the gasification / sublimation device, so that the volume of the phase change adjustment airbag increases, and then the volume of the lift gas shrinks, the internal pressure and the pressure difference of the main airbag 302 increase.

[0019] In an embodiment, the composite main airbag is also provided with an internal airbag, and an air pump is arranged to suck or exhaust the air in the internal airbag to change the volume of the internal airbag, thereby changing the pressure difference of the main airbag, providing favorable pressure difference conditions for the phase change adjustment airbag, assisting in a height change, and keeping the pressure difference of the balloon within the safety range.

[0020] In an embodiment, the internal airbag is arranged inside the internal phase change adjustment airbag; when the height needs to be lowered, firstly, the phase change adjustment airbag is contracted through the liquefaction / condensation device, the lift gas is dispersed, the pressure is reduced, and the pressure difference is reduced to near an allowable lower limit of the safety pressure difference, so as to make a flow rate of an air suction by the air pump as large as possible; when the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches an upper limit of an effective air suction pressure difference, an air intake is stopped to reduce a power consumption of the air pump, and the internal phase change adjustment airbag is continuously contracted;

[0021] when the height needs to be raised, firstly, the internal phase change adjustment airbag is expanded through the gasification / sublimation device, the lift gas tightens and the pressure increases, and the pressure difference is increased to near an allowable upper limit of the safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching a lower limit of a safety pressure difference in an exhaust process of the air pump; when the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to an allowable lower limit of the pressure difference of the main airbag, the air exhaust is stopped, and the internal phase change adjustment airbag is continuously expanded.

[0022] Whether a pressure difference of a sphere is in a safety range is a lifeline to determine whether a balloon may work continuously for a long time. By adopting the technology according to the application, an active control of the safety pressure difference is realized, which not only fundamentally changes a passive situation that the existing balloon resists only by exhausting limited lift gas resources, or by a sphere material selection and a special structure, but also fundamentally resolves a bad influence of the air pump working with the internal airbag on the pressure difference of the sphere. More importantly, different from an idea of active pressure maintaining that requires the unreliable rotating Yin-yang ball with a huge power consumption to realize the day-night cycle, the technology according to the application fundamentally realizes the active day- night cycle for pressure difference safety control. Dual external phase is used to realize the pressure difference safety control in a redundancy mode.

[0023] In order to better realize the change of the working height of the balloon that may be required by the task, aiming at the demanding requirements of the existing composite air pump on the internal and external pressure differences of gas, the technology according to the application not only provides a redundancy mode of directly adjusting the height through phase change, but also creates favorable pressure difference conditions for the working of the composite air pump. More importantly, a whole process of height change control always ensures that the pressure difference of the sphere is always in a safety range, s0 as to realize the optimal coordination between a height control and a pressure difference control. BRIEF DESCRIPTION OF THE FIGURES

[0024] FIG. 1 1s a schematic diagram of an overall structure according to embodiment 1.

[0025] FIG. 2 is a flow chart of an pressure difference adjustment method according to embodiment 1.

[0026] FIG. 3 is a schematic diagram of an overall structure according to embodiment 2.

[0027] FIG. 4 is a flow chart of a pressure difference adjustment method according to embodiment 2.

[0028] FIG. 5 is a schematic diagram of an overall structure according to embodiment 3.

[0029] FIG. 6 is a flow chart of a pressure difference adjustment method according to embodiment 3.

[0030] FIG. 7 is a schematic diagram of an overall structure according to embodiment 4.

[0031] FIG. 8 is a flow chart of a pressure difference adjustment method according to embodiment 4.

[0032] FIG. 9 is a schematic diagram of an overall structure according to embodiment 5.

[0033] FIG. 10 is a flow chart of a pressure difference adjustment method according to embodiment 5.

[0034] FIG. 11 1s a schematic diagram of an overall structure according to embodiment 6.

[0035] FIG. 12 is a flowchart of a pressure difference adjustment method according to embodiment 6.

[0036] In the figures: 302, main airbag; 34, lift gas; 306, emergency return exhaust valve; 38, load basket; 310, ballast; 312, knot rope and its attached safety control device; 314, internal airbag; 316, internal air; 318, air pump; 330, phase change adjustment airbag; 332, phase change working medium gas; 334, liquid / solid working medium storage tank; 336, liquefaction / condensation device; 338, gasification / sublimation device; 340, phase change electronics and accessories; 362, special basket for phase change system. DETAILED DESCRIPTION OFTHE EMBODIMENTS

[0037] The application will be explained in further detail below with reference to the drawings and specific embodiments.

[0038] Embodiment 1

[0039] FIG. 1 shows a single-sphere high-altitude balloon with an external phase change adjustment airbag (referred to as an external phase single body for short). The phase change adjustment airbag is arranged outside a main airbag and below a load basket. A phase change working medium gas is communicated with the inside of the phase change adjustment airbag through a liquefaction / condensation device and a gasification / sublimation device, and is controlled by phase change electronics and accessories.

[0040] A volume change of the phase change adjustment airbag 330 directly causes a buoyancy change and a height change of a balloon system, and then an ambient atmospheric pressure changes, thus indirectly causing a pressure difference change of the main airbag 302.

[0041] A process of indirectly adjusting a pressure difference of the single-sphere high- altitude balloon with the phase change airbag is shown in FIG. 2; an allowable lower limit pam and an allowable upper limit pam of the balloon pressure difference are determined in advance according to a design and a ground test, and an appropriate value slightly larger than the lower limit is further set as a conservative lower limit pam+>pam and an appropriate value slightly smaller than the upper limit is set as a conservative upper limit pam-<pam. If the pressure difference of the main airbag 302 exceeds the conservative upper limit pam-, the phase change working medium gas 332 in the phase change adjustment airbag 330 is liquefied / condensed by the liquefaction / condensation device 336, so that the volume of the phase change adjustment airbag is reduced, which directly causes the buoyancy and the height of the balloon system to decrease, and then the ambient atmospheric pressure increases, thus indirectly causing the pressure difference of the main airbag 302 to decrease; if the pressure difference of the main airbag 302 exceeds the conservative lower limit pam, a liquid / solid working medium in a storage tank is gasified / sublimated by the gasification / sublimation device 338, so that the volume of the phase change adjustment airbag increases, directly causing the buoyancy and the height of the balloon system to increase, and then the ambient atmospheric pressure decreases, thus indirectly causing the pressure difference of the main airbag 302 to increase; otherwise, the pressure difference of the main airbag is in a safety range; if a safety margin of the pressure difference is large, and there is still margins for a phase change drive and a ballast, the height of the main airbag of a lift gas may be properly restored through a phase change. As an example, the height of the balloon is adjusted through the phase change airbag; the balloon drops from an altitude of 20 km to 18 km, an external pressure increases, and the balloon pressure difference formed by thermal radiation is greatly and sharply reduced. If there is no phase change airbag, the balloon is powerless to resist, and even cause the sphere to break.

[0042] Embodiment 2

[0043] FIG. 3 shows a composite sphere high-altitude balloon with the external phase change adjustment airbag (referred to as an external phase change complex for short). In this embodiment, the phase change adjustment airbag is arranged outside the main airbag and below the load basket. The liquid / solid working medium is communicated with the inside of the phase change adjustment airbag through the liquefaction / condensation device and the gasification / sublimation device, and is controlled by the phase change electronics and accessories. Moreover, an internal airbag is arranged in the main airbag, and an air pump is arranged at an air port of the internal airbag.

[0044] The air pump 318 is used to suck some air from the outside of the main airbag into the internal airbag 314 or exhaust some air from the internal airbag to the outside of the main airbag, thereby adjusting the height of the balloon. The phase change adjustment airbag overcomes a limitation of using the air pump alone to a certain extent, plays an auxiliary role in a height adjustment, and ensures that the pressure difference of the main airbag is within a safety range. Under normal circumstances, the pressure difference of the main airbag is within a safety range, and an internal air pressure of the main airbag is generally higher than an external atmospheric pressure; the air pump works to suck the external air into the internal airbag and transport the air from a low-pressure end to a high- pressure end, so the smaller the pressure difference is, the smaller the power consumption of the air pump is, the greater the pressure difference is, the more difficult the work is, and the higher the altitude is, the more difficult the work is; the power consumption is a nonlinear function of the pressure difference and a volume flow rate, and a mass flow rate is a product of a source air density and the volume flow rate; the volume flow rate is a nonlinear function of the altitude and the pressure difference; the pressure difference pa pm (h) when the volume flow rate gradually decreases to zero at different heights is called an upper limit of an effective air suction pressure difference of the air pump; the upper limits decrease with the increase of the altitude, and may be fitted in combination with nonlinear curves given by a manufacturer and the ground test results, so as to facilitate a control and a use.

[0045] FIG. 4 shows a process of the external phase change airbag assisting in changing the height safely. Keep the pressure difference of the main airbag in the safety range all the time, and provide an assistance for the height change as much as possible, which can not only indirectly assist in improving an efficiency of the air pump through a pressure difference adjustment, but also directly increase the height.

[0046] When the height needs to be lowered, the phase change adjustment airbag is contracted first to help lower the height and reduce the pressure difference to near an allowable lower limit of a safety pressure difference, so as to make the flow rate of the air suction by the air pump as large as possible. When the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches the upper limit pa_pm (h) of the effective air suction pressure difference, an air intake is stopped to reduce the power consumption of the air pump, and the phase change adjustment airbag is continuously contracted. Otherwise, see if a target height has been reached, if the target height has not been reached, the air pump continues to suck air from outside the sphere.

[0047] When the height needs to be raised, the phase change adjustment airbag is expanded first to help raise the height and increase the pressure difference to near an allowable upper limit of the safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching the lower limit of the safety pressure difference too quickly in an exhaust process of the air pump. When the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to the allowable lower limit of the pressure difference of the sphere, an air exhaust is stopped, and the phase change adjustment airbag is continuously expanded. Otherwise, see if a target height has been reached; if the target height has not been reached, the air pump continues to exhausts air from the internal airbag to the outside of the sphere.

[0048] Embodiment 3

[0049] FIG. 5 shows a single-sphere high-altitude balloon with an internal phase change adjustment airbag (referred to as an internal phase single body for short). The phase change adjustment airbag is located inside the main airbag, and a special basket for a phase change system is arranged between the main airbag and the load basket. The liquid / solid working medium is communicated with the inside of the phase change adjustment airbag through the liquefaction / condensation device and the gasification / sublimation device, and controlled by the phase change electronics and accessories; the liquefaction / condensation device 336, the gasification / sublimation device 338 and the phase change electronics and accessories 340 form a phase change adjustment system and are installed in the special basket 362 for the phase change system.

[0050] The volume change of the internal phase change adjustment airbag 330 directly causes the lift gas 304 in the main airbag to show an inverse volume change; therefore, an internal gas pressure and the internal and external pressure differences change, and a floating weight balance is not changed, so the height change is not adversely affected. A process of directly adjusting the pressure difference of the main airbag with the internal phase change airbag is shown in FIG. 6. In view of a diurnal variation of the temperature and the pressure of the lift gas, if the pressure difference of the main airbag 302 exceeds the conservative upper limit, the phase change working medium gas 332 in the phase change adjustment airbag is liquefied / condensed by the liquefaction / condensation device 336, so that the volume of the phase change adjustment airbag is reduced and an expansion space 1s left for the lift gas, and then the volume of the lift gas 304 expands, the internal pressure and the pressure difference of the main airbag 302 decrease, a rising trend of the pressure difference is slowed down and a stress degree of the spherical structure is reduced; if the pressure difference of the main airbag exceeds the conservative lower limit, the liquid / solid working medium in the storage tank 334 is gasified / sublimated by the gasification / sublimation device 338, so that the volume of the phase change adjustment airbag increases, and then the volume of the lift gas 304 shrinks, the internal pressure and the pressure difference of the main airbag 302 increase, and a failure of a shape preserving of the sphere caused by the low temperature of the lift gas is offset (at this time, the pressure difference has been reduced to near zero pressure difference). If there is no phase change adjustment airbag, the balloon is powerless to resist, and even cause the sphere to break. Based on the internal phase change adjustment airbag, the pressure difference is directly adjusted without affecting the height change, so that the pressure difference of the high- altitude balloon is kept in a safety range all day and night.

[0051] Taking the volume of 5000 cubic meters as a benchmark for analysis, in the design of the main airbag, the main airbag itself undertakes a pressure difference fluctuation caused by the average temperature fluctuation. When a temperature fluctuation is large, the excess fluctuation is adjusted and offset by the phase change system composed of the internal phase change electronics and accessories. In practical experience, an average range of the diurnal temperature fluctuation is 227-248 K and a limit range is about 214-259 K, and the volume of the phase change airbag is about 500 cubic meters; and a complete phase change duration may be selected as 6 hours, a required volume phase change rate is 100 cubic meters / hour, with reference to a frequency of the diurnal temperature fluctuation and a consideration of minimizing a stress level of the main airbag.

[0052] Embodiment 4

[0053] FIG. 7 shows a composite sphere high-altitude balloon with the internal phase change adjustment airbag (referred to as an internal phase composite body for short). The phase change adjustment airbag is located in the main airbag, and the internal airbag is located in the phase change adjustment airbag. The special basket for the phase change system is arranged between the main airbag and the load basket. The liquid / solid working medium is communicated with the inside of the phase change adjustment airbag through the liquefaction / condensation device and the gasification / sublimation device, and controlled by the phase change electronics and accessories; the liquefaction / condensation device 336, the gasification / sublimation device 338 and the phase change electronics and accessories 340 form the phase change adjustment system and are installed in the special basket 362 for the phase change system. The air pump is arranged at the air port of the internal airbag.

[0054] A flow of an altitude hold pressure maintaining mode is shown in FIG. 8. Different from the external phase composite body, the change of the internal phase change adjustment airbag only indirectly assists the height change, unlike the external phase, which may also directly adjust the height.

[0055] When the height needs to be lowered, firstly, the internal phase change adjustment airbag is contracted through liquefaction / condensation, and then the lift gas is dispersed, the pressure is reduced, and the pressure difference is reduced to near the allowable lower limit of the safety pressure difference, so as to make the flow rate of the air suction by the air pump as large as possible. When the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches the upper limit pa_pm (h) of the effective air suction pressure difference, the air intake is stopped to reduce the power consumption of the air pump, and the internal phase change adjustment airbag is continuously contracted. Otherwise, see if the target height has been reached; if the target height has not been reached, the air pump continues to suck air from outside the main airbag.

[0056] When the height needs to be raised, firstly, the internal phase change adjustment airbag is expanded through gasification / sublimation, and then the lift gas tightens and the pressure increases, and the pressure difference is increased to near the allowable upper limit of the safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching the lower limit of the safety pressure difference too quickly in the exhaust process of the air pump. When the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to the allowable lower limit of the pressure difference of the main airbag, the air exhaust is stopped, and the internal phase change adjustment airbag is continuously expanded. Otherwise, see if the target height has been reached; if the target height has not been reached, the air pump continues to exhausts air from the internal airbag to the outside of the main airbag.

[0057] Embodiment 5

[0058] The single-sphere high-altitude balloon with external and internal phase change adjustment airbags (referred to as dual phase single body for short) is shown in FIG. 9. The dual phase single body includes two phase change adjustment airbags, which are respectively positioned inside the main airbag to form an internal phase change adjustment and positioned outside the main airbag to form an external phase change adjustment. The special basket for the phase change system is arranged below the main airbag, and a phase change adjustment system dedicated to the internal phase change adjustment airbag is arranged in the special basket for the phase change system. A phase change adjustment system dedicated to the external phase change adjustment airbag is arranged in a load basket

[0059] An altitude hold working mode has a redundant and safe pressure maintaining capability. For example, when the internal phase change is available normally, the internal phase change is preferred for pressure maintaining without causing a height fluctuation; otherwise, the external phase change is adopted for pressure maintaining; it is also possible that the internal and external phase changes are mixed to maintain pressure; for example, when a residual liquefaction capacity of the internal phase change is insufficient, a combination of external liquefaction and internal gasification is adopted, so the mode has certain flexibility.

[0060] The organic combination of a certain height adjustment ability of the external phase change with a characteristic of direct pressure adjustment of the internal phase change may better maintain the pressure and adjust the height, as shown in FIG. 10. If the height needs to be raised, a buoyancy height is directly raised through an external phase change gasification / sublimation, resulting in the decrease of external atmospheric pressure and the increase of the pressure difference of the main airbag. Therefore, if the conservative lower limit of the pressure difference has not been exceeded, and the internal phase change adjustment airbag has not been completely contracted, the pressure difference of the sphere is reduced to the greatest extent by the internal phase change liquefaction / condensation. Then, the buoyancy height is directly increased by the external phase change gasification / sublimation, and when the pressure difference increases to the conservative upper limit, the external phase change gasification / sublimation is suspended, and the internal phase change liquefaction / condensation is continued; otherwise, the external phase change gasification / sublimation is continued until the target height is reached (or a residual capacity of the external phase gasification / sublimation is exhausted). Similarly, a process of lowering the height is summarized: first, the pressure difference of the main airbag is adjusted to the conservative upper limit by an internal phase change gasification / sublimation, and then the buoyancy height is lowered by an external phase change liquefaction / condensation; when the pressure difference is reduced to the conservative lower limit, the external phase change liquefaction / condensation is suspended, and the internal phase change gasification / sublimation is continued for pressurization; otherwise, the external phase change liquefaction / condensation is continued until the target altitude is reached (or the residual capacity of the external phase liquefaction / condensation is exhausted).

[0061] Embodiment 6

[0062] FIG. 11 shows a composite sphere high-altitude balloon with the external and internal phase change adjustment airbags (referred to as a dual phase composite body for short). The dual phase composite body includes two phase change adjustment airbags, which are respectively positioned inside the main airbag to form the internal phase change adjustment and positioned outside the main airbag to form the external phase change adjustment. The internal airbag is also arranged inside the internal phase change adjustment airbag. The air pump is arranged at the air port of the internal airbag. The special basket for the phase change system is arranged below the main airbag, and the phase change adjustment system dedicated to the internal phase change adjustment airbag is arranged in the special basket for the phase change system. The phase change adjustment system dedicated to the external phase change adjustment airbag is arranged in the load basket.

[0063] The altitude hold pressure maintaining mode is similar to that of the dual phase single body in embodiment 5 and has a redundancy capability.

[0064] In a height adjustment mode, both the external phase change and the internal airbag have the ability to adjust the height, but the two parts have different effects on the pressure difference, so the two parts should complement each other by the following steps: using the phase change to create required pressure difference conditions for an operation of the air pump; reasonably and flexibly arranging priorities of an external phase height adjustment and an air pump height adjustment; and in a process of height adjustment, and choosing the priority of safety pressure difference guarantee with the external phase or the internal phase reasonably and flexibly. In a specific implementation, the steps mentioned above may be flexibly applied according to design parameters and actual working conditions of the whole balloon system. FIG. 12 only shows a specific demonstration strategy.

[0065] When the height needs to be lowered, considering that the external phase change reduces the pressure difference while lowering the height, which is conducive to have a good initial condition of low pressure difference when the air pump sucks air later, so the external phase change liquefaction / condensation is implemented first; if the target height has not been reached, and an optimal initial pressure difference required for the air suction by the air pump has not been reached, the external phase change liquefaction / condensation or the internal phase change liquefaction / condensation is flexibly chosen to continue to reduce the pressure difference; otherwise, the air pump is started to suck air to reduce the height; if the target height is still not reached, and the pressure difference has exceeded the upper limit pq pm (h) of the effective air suction pressure difference of the air pump, the external phase change liquefaction / condensation or the internal phase change liquefaction / condensation is flexibly chosen to reduce the pressure difference. Therefore, this process reflects that the external phase change liquefaction / condensation is organically combined with the air suction by the air pump to realize an optimal height adjustment; the external phase change liquefaction / condensation is organically combined with the internal phase change liquefaction / condensation to realize an optimal pressure maintaining; and the pressure maintaining creates a good pressure difference condition for the air pump to work.

[0066] When the height needs to be raised, considering that the external phase change increases the pressure difference while raising the height, so the external phase change gasification / sublimation is implemented first, so as to prevent the pressure difference of the sphere from exceeding the safety lower limit due to the premature exhaust of the air pump; if the target height has not been reached, and the pressure difference of the sphere has not reached the safety upper limit, the external phase change gasification / sublimation or the internal phase change gasification / sublimation is flexibly chosen to continue to increase the pressure difference; otherwise, the air pump is started to exhaust air to raise the height; if the target height is still not reached, and the pressure difference of the sphere has exceeded the safety lower limit due to continuous air exhaust, the external phase change gasification / sublimation or the internal phase change gasification / sublimation is flexibly chosen to increase the pressure difference. Therefore, this process reflects that the external phase change gasification / sublimation is organically combined with the air exhaust by the air pump to realize the optimal height adjustment; the external phase change gasification / sublimation is organically combined with the internal phase change gasification / sublimation to realize the optimal pressure maintaining; and the pressure maintaining creates the good pressure difference condition for the air pump to work.

[0067] The above embodiments are not intended to limit the application, and the application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the technical field within the technical scheme of the application also belong to a protection scope of the application.

Claims

WHAT IS CLAIMED IS:

1. A high-altitude balloon with phase change adjustment airbag, comprising: a main airbag; a load basket for equipping task equipment and loads; a phase change adjustment airbag for directly or indirectly adjusting a pressure difference of the high-altitude balloon to maintain the pressure difference within a safety range when a height of the balloon changes; a phase change working medium gas for filling the phase change adjustment airbag; and phase change equipment for regulating and controlling a volume of the phase change working medium gas in the phase change adjustment airbag; the phase change equipment comprises a liquefaction / condensation device for liquefying / condensing the phase change working medium gas; a gasification / sublimation device for gasifying / sublimating the phase change working medium; a storage tank for storing a liquid / solid working medium; phase change electronics and accessories; and a control system for controlling the phase change equipment and changing the volume of the phase change adjustment airbag without changing a weight of a whole balloon system, so as to cause an appropriate change of the balloon pressure difference and keep the balloon pressure difference within the safety range; the phase change adjustment airbag is one of a single configuration inside the main airbag, a single configuration outside the main airbag, a composite configuration inside the main airbag, a composite configuration outside the main airbag, a single internal-external hybrid configuration and a composite internal-external hybrid configuration; a method for adjusting the pressure difference and the height of the high-altitude balloon with phase change adjustment airbag is as follows: in the single configuration inside the main airbag and the single configuration outside the main airbag, the phase change adjustment airbag is adjusted according to the pressure difference of the main airbag exceeding a conservative upper / lower limit to meet height adjustment requirements; in the composite configuration outside the main airbag, an internal airbag is also arranged in the composite main airbag, and the airbag is connected with an air pump; when the height needs to be lowered, the phase change adjustment airbag is contracted first to help lower the height and reduce the pressure difference to near an allowable lower limit of a safety pressure difference, so as to make a flow rate of an air suction by the air pump as large as possible; when the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches an upper limit of an effective air suction pressure difference, an air intake is stopped to reduce a power consumption of the air pump, and the phase change adjustment airbag is continuously contracted; otherwise, see if a target height has been reached; if the target height has not been reached, the air pump continues to suck air from outside the sphere; when the height needs to be raised, the phase change adjustment airbag is expanded first to help raise the height and increase the pressure difference to near an allowable upper limit of a safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching the lower limit of the safety pressure difference too quickly in an exhaust process of the air pump; when the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to an allowable lower limit of the pressure difference of the sphere, an air exhaust is stopped, and the phase change adjustment airbag is continuously expanded; otherwise, see if the target height has been reached; if the target height has not been reached, the air pump continues to exhausts air from the internal airbag to the outside of the sphere; in the composite configuration inside the main airbag, the internal airbag is also arranged in the composite main airbag, and the airbag is connected with the air pump; when the height needs to be lowered, firstly, the internal adjustment airbag is contracted through liquefaction / condensation, a lift gas is dispersed and the pressure is reduced, and the pressure difference is reduced to near the allowable lower limit of the safety pressure difference, so as to make the flow rate of the air suction by the air pump as large as possible; when the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches the upper limit of the effective air suction pressure difference, the air intake is stopped to reduce the power consumption of the air pump, and the internal phase change adjustment airbag is continuously contracted; otherwise, see if the target height has been reached; if the target height has not been reached, the air pump continues to suck air from outside the main airbag; ‘when the height needs to be raised, firstly, the internal phase change adjustment airbag is expanded through gasification / sublimation, the lift gas tightens and the pressure increases, and the pressure difference is increased to near the allowable upper limit of the safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching the lower limit of the safety pressure difference too quickly in the exhaust process of the air pump; when the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to the allowable lower limit of the pressure difference of the main airbag, the air exhaust is stopped, and the internal phase change adjustment airbag is continuously expanded; otherwise, see if the target height has been reached; if the target height has not been reached, the air pump continues to exhausts air from the internal airbag to the outside of the main airbag; in the single internal-external hybrid configuration, adjust a contraction of the internal phase change adjustment airbag for the height adjustment, judge the contraction and the expansion of the internal phase change adjustment airbag, and judge that the pressure difference of the main airbag exceeds the conservative upper / lower limit, and adjust the external phase change adjustment airbag to meet the height adjustment requirements; in the composite internal-external hybrid configuration, when the height needs to be reduced, the external phase change liquefaction / condensation is implemented first; if the target height has not been reached, and an optimal initial pressure difference required for the air pump suction has not been reached, the external phase change liquefaction / condensation or the internal phase change liquefaction / condensation is flexibly chosen to continue to reduce the pressure difference; otherwise, the air pump is started to suck air to reduce the height; if the target height is still not reached, and the pressure difference has exceeded the upper limit of the effective air suction pressure difference of the air pump, the external phase change liquefaction / condensation or the internal phase change liquefaction / condensation is flexibly chosen to reduce the pressure difference; when the height needs to be raised, the external phase change gasification / sublimation is implemented first, so as to prevent the pressure difference of the sphere from exceeding the safety lower limit due to the premature exhaust of the air pump; if the target height has not been reached, and the pressure difference of the sphere has not reached the safety upper limit, the external phase change gasification / sublimation or the internal phase change gasification / sublimation is flexibly chosen to continue to increase the pressure difference; otherwise, the air pump is started to exhaust air to raise the height; if the target height is still not reached, and the pressure difference of the sphere has exceeded the safety lower limit due to continuous air exhaust, the external phase change gasification / sublimation or the internal phase change gasification / sublimation is flexibly chosen to increase the pressure difference.

2. The high-altitude balloon with phase change adjustment airbag according to claim 1, wherein the phase change adjustment airbag arranged outside the main airbag changes the volume of the phase change adjustment airbag through the phase change equipment, thereby directly changing the height of the balloon and indirectly changing the pressure difference of the balloon, so that the pressure difference of the balloon is kept within the safety range.

3. The high-altitude balloon with phase change adjustment airbag according to claim 2, wherein when the pressure difference of the main airbag exceeds the conservative upper limit, the phase change working medium gas in the phase change adjustment airbag is liquefied / condensed by the liquefaction / condensation device, so that the volume of the phase change adjustment airbag is reduced, which directly causes a buoyancy and the height of the balloon to decrease, and then an ambient atmospheric pressure increases, thus indirectly causing the pressure difference of the main airbag to decrease; when the pressure difference of the main airbag exceeds the conservative lower limit, the liquid / solid working medium in the storage tank is gasified / sublimated into the phase change working medium gas by the gasification / sublimation device, and then the gas is transported to the phase change adjustment airbag, so that the volume of the phase change adjustment airbag increases, directly causing the buoyancy and the height of the balloon to increase, and then the ambient atmospheric pressure decreases, thus indirectly causing the pressure difference of the balloon to increase.

4. The high-altitude balloon with phase change adjustment airbag according to claim 1, wherein the phase change adjustment airbag arranged in the main airbag directly causes an appropriate change of the balloon pressure difference by changing the volume of the internal phase change adjustment airbag, so that the balloon pressure difference is kept within the safety range.

5. The high-altitude balloon with phase change adjustment airbag according to claim 4, wherein when the pressure difference of the main airbag exceeds the conservative upper limit, the phase change working medium gas in the phase change adjustment airbag is liquefied / condensed by the liquefaction / condensation device, so that the volume of the phase change adjustment airbag is reduced and an expansion space is left for the lift gas, and then the volume of the lift gas expands, an internal pressure and the pressure difference of the main airbag decrease, and a rising trend of the pressure difference is slowed down; when the pressure difference of the main airbag exceeds the conservative lower limit, the liquid / solid working medium in the storage tank is gasified / sublimated by the gasification / sublimation device, so that the volume of the phase change adjustment airbag increases, and then the volume of the lift gas shrinks, and the internal pressure and the pressure difference of the main airbag increase.

6. The high-altitude balloon with phase change adjustment airbag according to claim 1, wherein the air pump in the composite main airbag sucks or exhausts the air in the internal airbag to change the volume of the internal airbag, thereby changing the pressure difference of the main airbag, providing favorable pressure difference conditions for the phase change adjustment airbag, assisting in a height change, and keeping the pressure difference of the balloon within the safety range.

7. The high-altitude balloon with phase change adjustment airbag according to claim 6, wherein the internal airbag is arranged inside the internal phase change adjustment airbag; when the height needs to be lowered, firstly, the phase change adjustment airbag is contracted through the liquefaction / condensation device, the lift gas is dispersed, the pressure is reduced, and the pressure difference is reduced to near the allowable lower limit of the safety pressure difference, so as to make the flow rate of the air suction by the air pump as large as possible; when the air pump sucks air and the height decreases, the pressure difference of the main airbag increases; once the pressure difference reaches the upper limit of the effective air suction pressure difference, the air intake is stopped to reduce the power consumption of the air pump, and the internal phase change adjustment airbag is continuously contracted; when the height needs to be raised, firstly, the internal phase change adjustment airbag is expanded through the gasification / sublimation device, the lift gas tightens and the pressure increases, and the pressure difference is increased to near the allowable upper limit of the safety pressure difference, so as to prevent the pressure difference of the main airbag from approaching the lower limit of the safety pressure difference in the exhaust process of the air pump; when the air pump exhausts air and the height rises, the pressure difference of the main airbag decreases; once the pressure difference decreases to the allowable lower limit of the pressure difference of the main airbag, the air exhaust is stopped, and the internal phase change adjustment airbag is continuously expanded.

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